Persistent covid-19 pneumonia and failure to develop anti-SARS-CoV-2 antibodies during rituximab maintenance therapy for follicular lymphoma

The global COVID-19 pandemic has been reported to inflict higher death rates in patients with hematologic malignancies compared with the general population.1 Proposed theoretical mechanisms include lymphopenia, which is often seen in this patient group, and suppressed immune function owing to the hematologic malignancy itself or because of treatment. We report the first case of persistent COVID-19 pneumonia that was still ongoing at 2 months after onset in a patient with follicular lymphoma (FL) undergoing rituximab maintenance therapy. The patient failed to develop anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin (Ig)G and IgM antibodies, which was most probably the result of prior rituximab therapy, and thus provoked this unusual chronic state of COVID-19 pneumonia.